Condensate disposal system

ABSTRACT

Apparatus is disclosed for disposing of condensate from the evaporator of a refrigeration air conditioning system. A fan in a fan shroud is provided to move a current of air over the condenser and to pressurize the condenser plenum. An aperture through the fan shroud is adjacent to a low point in a base pan designed to collect the condensate. A baffle or air duct adjacent the aperture on the inlet side of the fan shroud directs air from the aperture back into the fan. Condensate is atomized by the return flow of air through the aperture, directed through the fan and onto the condenser of the refrigeration system where it is evaporated. The air duct may be in the form of an upstanding conduit for an air conditioner having a fan with a horizontal axis. In a preferred arrangement the fan axis is tilted and a semi-cylindrical baffle tangent to the base pan opposite the aperture directs air flow back in a largely horizontal direction into the fan.

United States Patent [191 De Jarlais [4 1 Mar. 19, 1974 1 .CONDENSATE DISPOSAL SYSTEM [75] lnventor: Gordon M. De Jarlais, Frankfort,

Ind.

[73] Assignee: Lear Siegler, Inc., Santa Monica,

Calif.

[22] Filed: Sept 18, 1972 21 Appl. No.: 290,276 A Primary Examiner-William J. Wye Attorney, Agent, or Firm -Christie, Parker-8c Hale [s7 ABSTRACT Apparatus is disclosed for disposing of condensate from the evaporator of a refrigeration air conditioning system. A fan in a fan shroud is provided to move a current of air over the condenserand to pressurize the condenser plenum. An aperture through the fan shroud is adjacent to a low point in a base pan designed to collect the condensate. A baffle or air duct adjacent the aperture on the inlet side of the'fan shroud directs air from the aperture back into the fan. Condensate is atomized by the return flow of air through the aperture, directed through the fan and onto the condenser of the refrigeration system where it isevaporated. The air duct may be in the form of an upstanding conduit for an air conditioner having a fan with a horizontal axis. In a preferred arrangement the fan axis is tilted and a semi-cylindrical baffle tangent to the base pan opposite the aperture directs air flow back in a largely horizontal direction into the fan.

5 Claims, 6 Drawing Figures CONDENSATE DISPOSAL SYSTEM BACKGROUND OF THE INVENTION This invention relates to refrigeration systems, and more specifically, to apparatus for disposing of condensate produced by a self contained air conditioning systern.

A refrigeration system conventionally comprises a cyclic process which includes heating and compressing a refrigerant in its gaseous state,- feeding the heated and compressed gas to a condenser where the refrigerant is liquified by cooling while still under pressure, and feeding the pressurized liquid to an expansion valve where the liquid is depressurized and the temperature further reduced by a partial evaporation of the refrigerant. The cooled and depressurized refrigerant is then fed to an evaporator where it vaporizes as a result of taking heat from the evaporator and in turn the air flowing over the extended surface of the evaporator.

It is common knowledge that when refrigeration type air conditioning units areused on humid days, a considerable quantity of water from the air is condensed on the evaporator coils. It is mandatory, therefore, to provide means for disposing of the condensate.

In the past, some condensate disposal systems have used base pairs underneath the evaporator for collecting'the condensate and then have used pipes or drains to dispose thereof. Other condensate disposal systems eliminate condensate by projecting it onto the condenser coils where it is evaporated. The latter disposal system has proven most beneficial since it has allowed a refrigeration unit to be self-contained in that no dripping occurs, and furtherthe waterhelps cool the condenser of the refrigeration system.

Self-contained disposal systems of the past have used such devices as fan slinger rings, rotating rings, tabs or other apparatus attached to the condenser fan, which agitate or splash the condensate and project it as discrete droplets in the air stream from the condenser fan. The condensate droplets are then projected onto the condenser coil where they are evaporated. Such disposal systems not only eliminate condensate, but additionally increase the efficiency of the condenser by aiding it in cooling the compressed refrigerant. V

Disposal systems using rotating rings, tabs or the like, can not be used in some designs for picking up the condensate and projecting it onto the condenser. Large size slinger rings are fragile and for large diameter fans are prohibitively expensive. Further the increased fan diameter resulting from use of slinger rings may not be acceptable in some designs because of size limitations. As the axis of the fan deviates from horizontal the effectiveness of rotating rings, tabs and the like diminish. When the axis of the fan is vertical, this technique for condensate disposal is completely ineffective.

One solution proposed in the past has been to circulate air from the higher pressure side of the fan through a hole into a condensate sump on the low pressure side of the fan, a deflector then deflects the air flow towards the inlet stream into the fan. The return flow of air picks up water droplets and directs them into the main air flow through the fan. Such arrangements are shown for example in U.S. Pat., Nos. 3,089,314, Speaker, and 3,213,638, Speaker et al. In both of these references a slightly curved upstanding deflector sheet directs air .flow generally upwardly. Apparently it was found that the simple'deflector provided in the earlier U.S. Pat. No. 3,089,314 to Speaker was not sufficient for condensate removal. In the subsequent Speaker et al. U.S. Pat. No. 3,213,638 the velocity of air fiow is enhanced by providing a baffle near the periphery of the fan on the higher pressure side for high flow rates through the sump. Preferably the expense of the extra structure of the baffle and the entire extra air flow duct between the baffle and the aperture is avoided.

In some instances, such as for example, recreational vehicles wherein the air conditioner may be mounted on the roof or in some other location where a low profile is advantageous, it is desirable to.have a fan with the axis tilted at a very large angle from the horizontal. As mentioned above, as the plane of rotation of the fan approaches the vertical the use of slinger rings and the like becomes impossible. In addition, an arrangement as provided in the Speaker et al. patent becomes deficient since the air flow pattern is quite different.

It is therefore desirable to provide an improved condensate disposal system for. a self-contained refrigeration air conditioning system. Such a system preferably operates without slinger-rings, agitation rings, tabs or the like. Preferably it has a high atomization, pi'cleup and condensate disposal rate regardless of fan speed and is operative at minimum condensate depth in the base pan. It should provide condensate disposal with the fan axis at a largeangle from the horizontal.

BRIEF SUMMARY OF THE INVENTION Thus there is provided in practice of the present invention according to a preferred embodiment, an aperture through the fan shroud adjacent a low point in the condensate base pan of a refrigeration system. A deflector adjacent the aperture on the inlet side of the fan guides the air flow through the aperture and picked-up condensate into the path of airentering the fan, the condensate thereby being projected onto the condenser where it is evaporated.

DRAWINGS These and other features and advantages of the present invention will be appreciated as the same becomes better understood by reference to the following detailed description of a presently preferred embodiment when considered in conjunction with the drawings wherein:

FIG. 1 is a schematic diagram of the refrigeration system;

FIG. 2 is a fragmentary perspective view of part of a refrigeration system constructed according to a preferred embodiment of the present invention;

FIG. 3 is a fragmentary side sectional view of the system of FIG. 2;

FIG. 4 is a side semi-schematic view of a refrigeration system including an alternative embodiment of the present invention;

FIG. 5 is a plan view of the system of FIG. 4; and FIG. 6 is a sectional view of a portion of the embodiment of FIGS. 4 and 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 represents schematically a refrigeration system, such as an air conditioner. As is well-known, a gaseous refrigerant is compressed and heated in a compressor 1 and then liquefied by indirect heat exchange with outside air in a condenser 2. Following further cooling by expansion through an expansion valve 3, the refrigerant is passed in indirect heat exchange relationship with room air in an evaporator 4. Vaproization of the refrigerant in the evaporator coils cools room air flowing over the coils. A condenser fan 6 circulates outside air over the condenser for cooling it. An evaporator fan 7 circulates inside air over the evaporator for warming it and consequently cooling the air. Cooling of the room air produces condensation of water from the room air on the evaporator, the amount condensed being dependent upon the relative humidity of the room air and the extent of its cooling.

Referring to FIGS. 2 and 3, the condensed water or condensate from the evaporator (not shown) is collected in a base pan which extends along the bottom of the refrigeration unit. A condenser fan 14 is mounted within an opening 22 through a fan shroud 24. The fan and fan shroud have an inlet side 26 and an outlet side 28. The outside air is projected through opening 22 from inlet to outlet side by the fan operation. The inlet side of the fan is typically open to the outside ambient and is at substantially ambient pressure. The outlet side or plenum 28 has the condenser 12 forming one wall and the resistance to air flow through the condenser develops a greater ambient pressure within the plenum 28 between fan shroud 24 and condenser coil 12. The pressure differential between the inlet and outlet sides of fan shroud 24 is important to the condensate disposal system of the present invention.

As best seen in FIG. 3, an aperture 32 of relatively small dimensions is provided through the bottom of fan shroud 24 near a low point in base pan 20. Since, when the fan is operating, the plenum is at a higher pressure than the outside air at inlet side 26 of the fan, which is at ambient pressure, a small amount of air from the plenum will be forced back, in a return air flow, through aperture 32 to the inlet side of the fan shroud. A semicylindrical baffle 34 mounted on the inlet side 26 of fan shroud 24 forms a vertically extending air duct 35. The bafile has a pair of apertures 36 through the lower extent thereof so that the condensate accumulated in the base pan 20 will also flow into the air duct 35 defined by the baffle. I

As the condenser fan 14 is operated, the pressure differential between the linet and outlet sides of fan shroud 24 causes a high velocity return flow of air through aperture 32 and upwardly through the duct 35. Condensate 37 accumulated in base pan 20 that enters the air duct through the apertures 36 in the baffle 34 is entrained in' the high velocity air and carried through the duct in an upward direction. The high velocity return air flow through the aperture 32 additionally causes the condensate to be broken up into discrete droplets, i.e., atomized, as it is projected substantially vertically upwardly along the duct 35. After leaving-the open upper end of the air duct 35, the atomized condensate enters the path of outside air being forced through opening 22 by rotation of the fan. The discrete condensate droplets are thus forced into the opening, along with the incoming outside air, and onto condenser coil 12 where the condensate is evaporated. The baffle 34 in the embodiment of FIGS. 2 and 3 is asymmetrically located and hence the top edge is preferably tapered to bring the top of the duct near the periphery of the fan. The return flow air through aperture 32 keeps condensate from entering the outlet plenum side of the fan shroud. The condensate is thus maintained substantially on the inlet side of the shroud.

As pointed out above, evaporating the condensate on the condenser coil serves the additional purpose of aiding the condenser in the performance of its function of liquefying the refrigerant. The overall efficiency of the refrigeration system is thereby increased.

FIGS. 4-6 represent side, top, and fragmentary sectional views respectively of an alternative embodiment of air conditioner constructed according to principles of this invention. The same principle of utilizing the pressure differential between inlet and outlet sides of the fan shroud is employed to effectuate a return air flow through an aperture defined between the fan shroud and the base pan. This return air flow projects condensate into the air flow through the fan. In this embodiment, however, the configuration of the baffle and angular orientation of the fan are different from the embodiment of FIGS. 2 and 3.

Recently recreational vehicles such as campers, trailers, motor homes and the like have come into prominence. Correspondingly, air conditioning units therefor have also increased in sales and variety of designs. It is important, however, in designing an air conditioning unit for a recreational vehicle that the exposed vertical distance of the unit above the vehicle be kept to a minimum. Such minimum vertical extent not only has an asesthetic value, but also has a higher degree of safety.

The refrigeration unit of FIG. 4 is designed with recreational vehicles and the above height limitation in mind. The condenser fan 40 and condenser 41 are slanted at an angle of about 45 from the vertical so as to displace the least amount of vertical room. A sealed compressor 42 and evaporator-fan unit 43 are also provided in the compact air-conditioning system. To make the condensate disposal system of the present invention much more effective when used with an angularly disposed fan, a substantially semi-cylindrical baffle 44 is used with its longitudinal axis 44 disposed substantially parallel with base pan 46 of the system. An air flow aperture 47 through the bottom of the fan shroud 48 permits return air flow from the outlet side of the fan to the inlet side. The baffle 44 has a smoothly curving inner concave surface 49 on the side adjacent the aperture 47 and curving between the basepan 46 and the inlet side of the fan. The baffle is substantially tangent to the base pan at its lower edge opposite the aperture and curves up smoothly to a top edge that has a tangent at a large angle from the vertical. Condensate is free to flow around the ends of the baffle. Thus as air is forced back through aperture 47 by the pressure differential existing across the fan shroud 48, the water condensate in the base pan is forced against inner concave surface 49 and projected circumferentially along such surface. The return air flow and atomized condensate is then projected out of the baffle along a path substantially tangent to the concave surface 47 at the upper end of the baffle 44. This sends the return air flow in a largely horizontal direction back towards the fan. The direction of air flow into the fan is almost reverse to flow through the aperture although there is some upward component of flow away from the top edge of the baffle 44. The condensate droplets are projected into the path of outside air being forced through the fan shroud opening and are eventually evaporated in condenser coil 41.

Thus there is provided an improved condensate disposal system utilizing the fact that the air in the outlet plenum of the condenser fan is at a higher pressure than the inlet side of the fan. An aperture is provided between the fan shroud and base pan thereby allowing a return flow of air from the'condenser plenum at the higher pressure, to the inlet side of the fan at the lower pressure. A baffle at the inlet side of the fan adjacent the aperture guides the condensate into the path of incoming outside air, the condensate being forced through a duct in the baffle, in one embodiment, or circumferentially along the inner surface of the baffle, in an alternative embodiment, because of the return flow of air. The condensate is thus projected in discrete droplets into the flow of incoming outside air which carries the droplets onto the condenser coil where they are evaporated. Since it is not necessary to dip into condensate in the base pan with a fan ring or the like,

water is directed onto the condenser when a very low level is present in the base pan. No substantial amount of condensate ever collects in the pan. The air duct and curved baffle keep high velocity air flow for good water pick up and assure that the droplets reach the fan.

Although the present invention has been described with specific reference to an air conditioning unit, it will be apparent to one skilled in the art that the principles are applicable to any refrigeration system. Although the described embodiments have fans with horizontal-and tilted axes respectively, it will be apparent that the principles are well suited to a system with a vertical fan or a fan at any arbitrary angle. The specific structure of the aperture,shroud and the like can have considerable variation from that shown and described herein. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is'claime'd is:

1. In an air conditioning system including a condenser coil and a condenser fan having a horizontal axis of rotation mounted within an opening defined in a fan shroud, the shroud having an inlet side and an outlet side, the outlet side being adjacent the condenser coil and at a higher pressure than the inlet side responsive to fan rotation, and further including a substantially horizontal base pan disposed beneath the system for collecting condensate, improved apparatus for effecting removal of the condensate collected in the pan comprising: I

an aperture between the fan shroud and the base pan for allowing a return flow of air from the outlet side to the inlet side of the fan shroud, the return air occasioned bythe pressure differential between the inlet and outlet sides;

an upstanding air duct in fluid communication with the aperture on the inlet side of the fan shroud for guiding the air flow through the aperture into the path of air entering the fan shroud opening and projecting discrete droplets of condensate substantially vertically into the path of air entering the fan shroud opening; and

an aperture in the bottom of the air duct for admitting condensate into the air duct.

2. In an air conditioning system including a con- -denser coil and a condenser fan having an axis of rotation tilted relative to both the vertical and horizontal for minimum air conditioner height, said fan being mounted in an opening defined in a fan shroud, the shroud having an inlet side and an outlet side, the outlet side being adjacent the condenser coil and at a higher pressure than the inlet side responsive to fan rotation, and further including a base pan disposed beneath the system for collecting condensate, improved apparatus for effecting removal of the condensate collected in the pan comprising:

an aperture between the fan shroud and the base pan for allowing a return flow of air from the outlet side to the inlet side of the fan shroud, the return flow occasioned by the pressure differential between the inlet and outlet sides;

a semi-cylindrical baffle adjacent the aperture on the inlet side of the shroud for guiding the air flow through the-aperture into the path of air entering the opening in the shroud, said semi-cylindrical baffle being open at at least one end and having its longitudinal axis parallel with the base pan and normal to the axis of rotation of the fan for reversing the direction of air flow from the aperture and directing it towards the openingin the fan shroud.

3. In an air conditioning system as defined in claim 2 an improved baffle wherein the baffle at its lower edge is substantially tangential to the base pan and extends in a smooth curve to its upper edge, a tangent at the upper edge of the baffle being at a large angle from the vertical for directing air flow in a largely horizontal direction. I

4. An air conditioner comprising? a refrigeration system including an evaporator and a condenser;

a condenser fan having itsaxis of rotation slanted relative to the horizontal at a substantial angle;

a fan shroudat least partly defining a condenser plenum for maintaining a pressure therein higher than ambient;

a base pan for collecting condensate from the evaporator outside the condenser plenum and at a lower pressure than the condenser plenum and for conveying condensate to a relatively lower point;

. an air flow aperture through the fan shroud adjacent the low point in the base pan for directing air flow from the condenser into the base pan; and

a concave deflector smoothly curling from the aperture towards the fan for directing air flow from the aperture in a largely horizontal direction towards the axis of rotation of the fan at least one portion of the concave side of the deflector being in fluid communication with the base pan for admitting I condensate to the concave side.

5. An air conditioner as defined in claim 4 wherein the deflector comprises a substantially semi-cylindrical sheet having its longitudinal axis transverse to the axis of rotation of the fan and substantially tangent to the base pan at its lower edge. 

1. In an air conditioning system including a condenser coil and a condenser fan having a horizontal axis of rotation mounted within an opening defined in a fan shroud, the shroud having an inlet side and an outlet side, the outlet side being adjacent the condenser coil and at a higher pressure than the inlet side responsive to fan rotation, and further including a substantially horizontal base pan disposed beneath the system for collecting condensate, improved apparatus for effecting removal of the condensate collected in the pan comprising: an aperture between the fan shroud and the base pan for allowing a return flow of air from the outlet side to the inlet side of the fan shroud, the return air occasioned by the pressure differential between the inlet and outlet sides; an upstanding air duct in fluid communication with the aperture on the inlet side of the fan shroud for guiding the air flow through the aperture into the path of air entering the fan shroud opening and projecting discrete droplets of condensate substantially vertically into the path of air entering the fan shroud opening; and an aperture in the bottom of the air duct for admitting condensate into the air duct.
 2. In an air conditioning system including a condenser coil and a condenser fan having an axis of rotation tilted relative to both the vertical and horizontal for minimum air conditioner height, said fan being mounted in an opening defined in a fan shroud, the shroud having an inlet side and an outlet side, the outlet side being adjacent the condenser coil and at a higher pressure than the inlet side responsive to fan rotation, and further including a base pan disposed beneath the system for collecting condensate, improved apparatus for effecting removal of the condensate collected in the pan comprising: an aperture between the fan shroud and the base pan for allowing a return flow of air from the outlet side to the inlet side of the fan shroud, the return flow occasioned by the pressure differential between the inlet and outlet sides; a semi-cylindrical baffle adjacent the aperture on the inlet side of the shroud for guiding the air flow through the aperture into the path of air entering the opening in the shroud, said semi-cylindrical baffle being open at at least one end and having its longitudinal axis parallel with the base pan and normal to the axis of rotation of the fan for reversing the direction of air flow from the aperture and directing it towards the opening in the fan shroud.
 3. In an air conditioning system as defined in claim 2 an improved baffle wherein the baffle at its lower edge is substantially tangential to the base pan and extends in a smooth curve to its upper edge, a tangent at the upper edge of the baffle being at a large angle from the vertical for directing air flow in a largely horizontal direction.
 4. An air conditioner comprising: a refrigeration system including an evaporator and a condenser; a condenser fan having its axis of rotation slanted relative to the horizontal at a substantial angle; a fan shroud at least partly defining a condenser plenum for maintaining a pressure therein higher than ambient; a base pan for collecting condensate from the evaporator outside the condenser plenum and at a lower pressure than the condenser plenum and for conveying condensate to a relatively lower point; an air flow aperture through the fan shroud adjacent the low point in the base pan for directing air flow from the condenser into the base pan; and a concave deflector smoothly curling from the aperture towards the fan for directing air flow from the aperture in a largely horizontal direction towards the axis of rotation of the fan at least one portion of the concave side of the deflector being in fluid communication with the base pan for admitting condensate to the concave side.
 5. An air conditioner as defined in claim 4 wherein the deflector comprises a substantially semi-cylindrical sheet having its longitudinal axis transverse to the axis of rotation of the fan and substantially tangent to the base pan at its lower edge. 